''The Clerk of the House intervened to say that Chief Superintendent (Ed) Bateman had bamboozled the Serjeant and tricked her into keeping the matter from her immediate superiors.

''The Clerk went on to say that, while Chief Superintendent Bateman was a Metropolitan Police Officer, he also had a duty towards the House.''

Chief Supt Bateman is the officer in charge of Commons security.

Asked if he believed the police had targeted the consent of the Serjeant because they did not think they would be able to secure a warrant, he said: ''We have a word in Scotland called 'sleekit' and they were being sleekit, they were doing it in a sleekit way to get in.''

Scotland Yard immediately issued an angry denial and said it would prove to the committee that there was no substance to the allegations against the officer.

''At no point did Chief Superintendent Bateman, or any officer from the MPS, attempt to 'bamboozle' or 'trick' anyone in this matter and we strongly refute this,'' a spokeswoman said.

''There is a clear audit trail, including a letter and signed search consent form, which supports this and which will be presented to the Committee at the appropriate time.

''At no stage in the past year has Lord Martin ever brought these allegations to our attention, despite the enormous publicity the case has generated.''

Asked by Sir Menzies about his decision to make public the ''very serious'' allegations in his opening statement, Lord Martin said: ''I have met Chief Superintendent Bateman on a number of occasions and I have always found him to be professional and courteous.

''A blame was being put here. There was an admittance at that meeting that the Serjeant had kept matters back but that she was doing so because she had been tricked.

''I consider myself here to be speaking on oath even though I have not been asked to take an oath and I don't say something like that about someone who is a career officer unless it was said in that room and the only reason I mention it is that I am deeply concerned about the information being kept from me and a blame was being put on to someone else.''

The Serjeant ''did not dissent'' from the Clerk's suggestion at the meeting, he said.

Lord Martin said he would have stepped in to halt the police action had he known but was kept in the dark by officials about what was happening.

No minutes or records had been kept of the ''several'' meetings between the Serjeant and police officers in the lead-up to the controversial action, he revealed.

During one such meeting involving Chief Supt Bateman, on the day before Mr Green's arrest, she had left the officers in her room to put a ''what if'' scenario to the Clerk.

He had informed her that she had the authority to consent to a search but failed to either question why she wanted to know or refer the matter to the Speaker, Lord Martin complained.

In evidence to the MPs, including former Tory leader Michael Howard and ex-Home Secretary David Blunkett, Lord Martin repeatedly criticised both the Serjeant and the Clerk.

Ms Pay had first told him about the possibility of an MP being arrested the day before the raid but had told him the information was confidential, he said.

Quizzed as to why he did not check whether a warrant had been sought, he said: ''I took it that the person in charge of security had consulted her immediate superior. That's what I expected.''